diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 3b00624..7165958 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -289,12 +289,12 @@ abstract class DrupalCacheArray implements ArrayAccess {
   /**
    * A cid to pass to cache_set() and cache_get().
    */
-  private $cid;
+  protected $cid;
 
   /**
    * A bin to pass to cache_set() and cache_get().
    */
-  private $bin;
+  protected $bin;
 
   /**
    * An array of keys to add to the cache at the end of the request.